The Daf always provides fascinating insights, sometimes resolving questions that have baffled great minds for centuries.
מסכת שבת דף קיב עמוד ב
תנן התם: כל כלי בעלי בתים – שיעורן כרמונים. בעי רבי חזקיה: ניקב כמוציא זית, וסתמו, וחזר וניקב כמוציא זית, וסתמו, עד שהשלימו למוציא רימון, מהו? – אמר ליה רבי יוחנן: רבי, שנית לנו סנדל שנפסקה אחת מאזניו ותיקנה – טמא מדרס, נפסקה שניה ותיקנה – טהור מן המדרס אבל טמא מגע מדרס, ואמרינן לך: מאי שנא ראשונה – דהא קיימא שניה, שניה נמי – מתקנה ראשונה! ואמרת לן עליה: פנים חדשות באו לכאן. הכא נמי – פנים חדשות באו לכאן. קרי עליה: לית דין בר אינש! איכא דאמרי: כגון דין בר אינש
The Gemara discusses the question of a vessel that is repeatedly punctured with a hole that is large enough for an olive to emerge and sealed, until eventually, the total of all the holes would’ve been large enough for a pomegranate to emerge. Does this render the vessel pure and not susceptible to tamei, since it has the status of broken and not usable?
Rabbi Yochanan brings a proof and answers that the vessel will be pure since it is not the same vessel as before, it is a new entity, and we view it as a vessel with a hole large enough for a pomegranate, even though the individual small holes were sealed as they were created. Rabbi Chizkiya was so impressed by Rabbi Yochanan’s comment that he exclaimed about him, “This is not a human being!”
See full translation here.
From Rabbi Chizkiya’s response, we see that he was amazed at the explanation of Rabbi Yochanan. While it is clear and obvious to us that all the Tannaim and Amoraim were angels as the Gemara concludes: אמר רבי זירא אמר רבא בר זימונא: אם ראשונים בני מלאכים – אנו בני אנשים, ואם ראשונים בני אנשים – אנו כחמורים, ולא כחמורו של רבי חנינא בן דוסא ושל רבי פנחס בן יאיר, אלא כשאר חמורים, it seems that particularly in this explanation Rebbi Chizkiya saw that only an angel could have come up with it. The question is why? What is so unique about this explanation that it seems we would need an angel to have said it?
The ship of Theseus
To answer this perhaps we may need to understand the full ramifications of Rabbi Yochanan’s explanation. For in truth, Rabbi Yochanan resolved an age-old paradox that has plagued the greatest philosophers. The paradox is known as The Ship of Theseus.
The concept is one of the oldest in Western philosophy, having been discussed by the likes of Heraclitus and Plato ca. 500–400 BCE.
It is supposed that the famous ship sailed by the hero Theseus in a great battle was kept in a harbor as a museum piece, and as the years went by some of the wooden parts began to rot and were replaced by new ones, until, after a century or so, every part had been replaced. The question then is if the “restored” ship is still the same object as the original.
The vital question is, is it still the same ship? If not, at what point does it cease to be the ship of Theseus? Replacing one board may not be such a big deal. But what about when half of them are no longer original, most of them, or all of them?
Some philosophers say changing one plank alters the ship irrevocably. Others say if at least one original plank is still in the ship, it’s the real deal. Then there are those who posit that the monument remains Theseus’s ship throughout.
These two sides of the argument are called the Mereological Theory of Identity – the view that the identity of an object depends on the identity of its component parts – versus Spatio-Temporal Continuity Theory – the view that an object can change materials and retain a constant identity as long as the change is gradual and the form or shape of the object is preserved through the changes of its component materials.
In both philosophy of law and practical law, the paradox appears when the ownership of an object or of the rights to its name are disagreed on in court. For example, groups of people such as companies, sports teams, and musical bands may all change their parts and see their old members re-form into rivals, leading to legal actions between the old and new entities. Also, texts and computer programs may be edited gradually but so heavily that none of the original remains, posing the legal question of whether the owners of the original have any claim on the result.
As is obvious, besides the question of identity there are many legal ramifications to which there is no clear answer.
However, from our Daf it is obvious which side of the argument Rabbi Yochanan took. As Rabbi Yochanan explains, if ” פנים חדשות באו לכאן”, meaning if, by adding up all the ”new parts” and assuming it would have been deducted from the shoe or the utensil in one time, the object would not have stayed טמא, then although the change happened gradually and in reality now the shoe or utensil is whole we cannot say it is still טמא as we say פנים חדשות באו לכאן. Rabbi Yochanan is of the opinion that although the change happens slowly over time, the identity of an object depends on the identity of its component parts and if they change, the object is not the same object.
Rabbi Yochanan resolved what the answer to the Ship of Theseus is. Of course, Rabbi Yochanan knew there is a different way of looking at the identity of an object – the view that an object can change materials and retain a constant identity as long as the change is gradual and the form or shape of the object is preserved through the changes of its component materials. However in halacha, a decision needs to be made about how we look at the object, but how does one decide such an old and difficult paradox? Only an angel can! Which is why Rabbi Chizkiya proclaimed לית דין בר אינש!